1. Field of the Invention
The present invention relates to a cooling structure for a projection television, which properly cools heat generated from the inside of the projection television. More particularly, the present invention relates to a cooling structure for a projection television, which keeps the inside of the projection television clean and effectively cools the heated projection television.
2. Description of the Related Art
As well known to those skilled in the art, a projection television is a kind of picture display station. In the projection television, a strong light is irradiated to a picture formed on a picture display panel such as a LCD, thereby projecting the picture on the screen.
In order to project the picture formed on the picture display panel on the screen, the projection television must comprise a lamp system for irradiating the strong light. However, the strong light is accompanied with heat, thereby shortening the life span of the projection television product.
Further, the strong light irritated from the lamp system is also transmitted to the picture display panel, thereby exerting a bad effect upon the picture display panel, for example, a boiling phenomenon. Herein, the boiling phenomenon denotes the deterioration of the image quality of the screen due to the boiling of the liquid crystal of the picture display panel.
FIG. 1 is a longitudinal sectional view of a cooling structure of a conventional projection television.
As shown in FIG. 1, the conventional projection television comprises an optical engine assembly 7, a screen 1, and a refractive mirror 3. The optical engine assembly 7 includes a lamp system 7a for irradiating a strong light, a synthesis system 7b for generating a picture image to be projected, and a lens system 7 for properly retracting the light including the image. Herein, the light including the image from the optical engine assembly 7C is projected on the screen 1.
Further, the conventional projection television comprises a back cover 2. In combination with the screen 1, the back cover 2 forms a housing of the projection television, thereby protecting elements inside the projection television.
Moreover, the projection television comprises a suction fan 5 and an exhaust fan 6. The suction fan 5 serves to provide cold external air to the inside of the projection television so as to cool the heated projection television. The exhaust fan 6 serves to exhaust the heated air produced in the projection television to the outside.
A dust proof filter 4 is formed on the exterior of the suction fan 5. Impurities such as the dust within the air to be sucked are filtered by the dust proof filter 4, thereby keeping the inside of the projection television clean.
Arrows shown in FIG. 1 illustrate the circulation of the air to cool the projection television. The cold air is sucked from the outside to the inside of the projection television by the suction fan 5, and the internal heated air is exhausted to the outside by the exhaust fan 6, thereby circulating the air within the projection television.
However, the aforementioned cooling structure for the conventional projection television has several problems, as follows.
As the cooling structure is repeatedly used, the dust is accumulated on the dust proof filter. Therefore, the dust proof filter covered with the dust must be frequently replaced with a new one, thereby causing an inconvenience to a user. Furthermore, it is not easy to replace the dust proof filter with a new one.
When the efficiency of the dust proof filter is deteriorated, the dust cannot be perfectly filtered. Therefore, the non-filtered dust is introduced into the projection television and attached to the picture display panel or the screen, thereby deteriorating the image quality of the projection television.